1. Field of the Invention
The present invention relates generally to format conversion apparatus and file search apparatus, and in particular to those capable of searching for a file having been converted in format, as based on an attribute thereof provided before it is converted in format.
2. Description of the Related Art
Japanese Laid-Open Patent Publication No. 2002-269126 discloses a document management system assigning a document image a property for management. This system adds to a document image an attribute of a document type corresponding to a type of form identified, such as a report, date and time, and the like. Thus a document image can efficiently be assigned an attribute. Note that each document type is assigned an attribute as previously defined.
Documents, image files and the like may be converted to a portable document format (PDF) file by using application software such as software for example of PDF WRITER of Adobe Systems Incorporated.
To search among document files recorded in a computer for a desired file an application (an extension) used to create the file may be used therefor. However, if a document created by WORD, EXCEL or the like is converted to a PDF file, its extension would be “.pdf” and the EXPLORER or the like can no longer be used to use the extension as a keyword for search. In other words, in conventional art once a file has been changed in format the file can no longer be searched for by the type of the application used to create the file.